docs: clarify npm version patch behavior with prerelease versions

When the current version is a prerelease (e.g., 1.2.0-5), running
npm version patch will remove the prerelease suffix without incrementing
the patch number (e.g., 1.2.0-5 becomes 1.2.0 with npm version patch,
not 1.2.1).

This behavior was not documented, leading to confusion for developers
and incorrect guidance from LLMs trained on the incomplete documentation.

Note: The behavior of minor and major with prerelease versions is more
complex and depends on the current version numbers, so this change
focuses specifically on patch behavior which is consistent.

Fixes: #8637

Author: yashwantbezawada

docs/lib/content/commands/npm-version.md

@@ -18,7 +18,7 @@ Run this in a package directory to bump the version and write the new data back
 `npm-shrinkwrap.json`.
 
 The `newversion` argument should be a valid semver string, a valid second argument to [semver.inc](https://github.com/npm/node-semver#functions) (one of `patch`, `minor`, `major`, `prepatch`, `preminor`, `premajor`, `prerelease`), or `from-git`.
-In the second case, the existing version will be incremented by 1 in the specified field.
+In the second case, the existing version will be incremented by 1 in the specified field. **Note:** If the current version is a prerelease version, `patch` will simply remove the prerelease suffix without incrementing the patch version number. For example, `1.2.0-5` becomes `1.2.0` with `npm version patch`, not `1.2.1`.
 `from-git` will try to read the latest git tag, and use that as the new npm version.
 
 If run in a git repo, it will also create a version commit and tag.